Grinder having deformable grinder wheel



April 20, 1965 Tosl-no. MIKIYA GRINDER HAVING DEFORMABLE GRINDER WHEEL 3 Sheets-Sheet 1 Filed Oct. 11, 1963 Rm f4 0/ H,7 m 5 E M M 6/ I i! 0 z a H a w r W a April 20, 1965 I TOSHIO. MIKIYA 3,178,863

GRINDER HAVING DEFOHMABLE GRINDER WHEEL 5 Sheets-Sheet 2 Filed Oct. 11, 1963 April 20, 1965 TOSHIO. MIKIYA GRINDER HAVING DEFQRMABLE GRINDER WHEEL 3 Sheets-Sheet 5 Filed 001:. 11, 1963 1N VENTOR. 705/700 M/K/y4 United States Patent 3,178,863 GRINDER HAVING DEFORMABLE GRINDER WHEEL Toshio Mikiya, 1028-banchi, Tsutsumkata-machi, Ota-ku, Tokyo, Japan Filed Oct. 11, 1963, Ser. No. 315,639 6 Claims. (Cl. 51-373) This invention relates to grinders and has for an object the provision of a grinder which has an elastic abrasive wheel and which is especially adapted for use in buifing and polishing uneven surfaces.

Another object of the invention is the provision of a grinder of the above character whose abrasive wheel may increase or decrease its contact dimensions to the article to be ground so as to be able to change the grinding area at will.

A further object of the invention is to provide a grinder in which the grinding action is equally distributed over the grinding surface, even if the surface is not plane, so as to effect a uniform grinding of such an uneven surface.

A further object of the invention is to provide a grinder whose abrasive wheel may deform its shape in accordance with the surface-condition of the article to be ground, so that the abrasive Wheel fits well to the grinding surface.

With the above and other objects in view, the invention further includes the following novel features and details of construction, to be hereinafter more fully described, illustrated in the accompanying drawings and pointed out in the appended claims. In the drawings:

FIG. 1 is a perspective view of the first form of a grinder constructed to operate in accordance with the invention;

FIG. 2 is a side elevation of the grinder of FIG. 1;

FIG. 3 is a section as seen at AA of FIG. 2;

FIG. ,4 is a side view of the abrasive wheel portion of the grinder shown in FIGS. 1 to 3;

FIG. 5 is a side elevation of a second form of grinder;

FIG. 6 is a front view of the grinder of FIG. 5, showing some of parts removed;

FIG. 7 is a diagrammatical view of the abrasive wheel and illustrates that it fits well to an uneven surface;

FIG. 8 is a perspective view of a drum-shaped body of the abrasive wheel employing to the above grinders;

FIG. 9 is a perspective view of an abrasive member adapted to cover the drum-shaped body of FIG. 8, showing some of parts cut away;

FIG. 10 is a vertical sectional view of a third form of grinder; and

FIG. 11 is a detail sectional View of the abrasive wheel portion of the above-mentioned third form of grinder, illustrating the working state of the said abrasive wheel.

The same reference numerals are applied to corresponding parts in these three embodiments.

Referring first to FIGS. 1 to 4 which show the first embodiment of the invention, reference numeral 1 generally indicates the grinder body which has at its front part a forked arm 2 and is provided at its rear part an electric motor 3. The housing of the motor 3 connects with a handle 4 in which is embedded a cord 5 which connects the motor 3 to a source of electric power (not shown). The driving of the motor 3 is controlled by a handle switch 6.

Designated generally as 7 is a drum-shaped elastic abrasive wheel mounted on an axle 8. The axle 8 is carried by the forked arm 2 and has at its one end a pulley 9 for connecting with the pulley 10 of the motor 3 through an endless belt 11. Extended downwardly from the motor housing are brackets 12, 12 which carry rolls 13, 13, respectively. These rolls 13, 13 serve to place the machine on the plane a of an article to be ground. Reference ice numeral 14 is an auxiliary handle adapted to push the abrasive wheel 7 against the grinding surface a when desired to increase the grinding force.

The abrasive wheel 7 of this grinder consists of a drumshaped hollow body 50 which is formed something like a Rugby ball made from an elastic material such as rubber or synthetic resin. The hollow interior of the drum 50 may be filled with gas or liquid, viz. air or water. As described above, the axle 8 extends out of the both ends 15, 15 of the drum 50, and these portions are hermetically sealed by the provision of flanges 16, 16 of the axle 8 and nuts 17, 17 screwed onto the axle 8 in such manner that the flanges 16, 16 and the nuts 17, 17 close tightly the axlepierced ends 15, 15 of the drum 50. Both ends of the axle 8 are supported by bearings 18, 18, respectively. The tip end portions 2a, 2a of the forked arm 2 cooperate, respectively, with members 19, 19 to clamp therebetween, by screw bolts 20, 20, the bearings 18, 18. The pulley 9 is firmly connected to one end 8a of the axle 8.

The axle 8 has also a bore 51 of which one end opens into the hollow interior of the drum 50 at 21 and with other end communicates a valve chest 22 provided at the other end 8b of the axle 8.

This valve mechanism may be of a conventional type. In the preferred embodiment shown in FIG. 3, a ball valve 24 is urged toward its valve seat by means of a compressed coiled spring 23 so as to close hermetically the valve opening. When desired to supply air or Water into the interior of the drum 50, a plunger or the fluid pressure may easily push away the ball valve 24 against the compressed coiled spring 23 to open a fluid passage through the bore 51, but when the supply of such compressed air or water is stopped the ball valve 24 is restored by the spring 23 to the position shown in FIG. 3, and simultaneously the interior pressure of the supplied fluid itself cooperate with the spring 23 to prevent the supplied fluid from leaking out of the drum 50.

The drum 50 is covered with a sheet 26 of which surface serves as a grinding element. The cover sheet 26 is so shaped to conform with the drum 50 and has at its interior surface grooves 27, 27 which engages with projections 25, 25 on the surface of the drum 50. Thus the abrasive cover sheet 26 will not slip off of the drum 50 when rotated by the latter.

FIGS. 5 and 6 show a modified embodiment of the invention, in which the abrasive wheel 7 may deform its drum-like shape. This deformation is effected by two rollers 28, 28 placed on the upper surface of the elastic abrasive wheel 7. The rollers 28, 28 are carried by triangular side plates 29, 29 which have at the respective central portions a vertical guide slot 30. Inserted into the slots 30, 30 are pins 31, 31 screwed into a supporting member 32 extending from the grinder body 1. The supporting member 32 is provided with adjustable screw bolts 34, 34 which acts to push or pull a rod 35 connected at its ends to the abovementioned plates 29 and 29. By screwing the bolts 34, 34, the rollers 28, 28 vertically shift their position against the elastic abrasive wheel 7 to change its drum-like shape. This means that the abrasive wheel 7 can freely increase or decrease the contacting area to the plane of article to be ground.

FIG. 7 shows how the abrasive wheel 7 of the invention can satisfactorily buff and polish an uneven surface such as shown as b.

Referring now to FIGS. 10 and 11, there illustrates a further modified embodiment of the invention. In this third form of grinder, the grinder body 1' is provided with a L-shaped grinder head 35 in which are disposed bevel gears 39 and 40 for transmitting the rotation of the motor shaft 37 to a stem 36. Into the lower end portion of the stem 36 is screwed a bored axle 41 adapted to fix Screwed onto the axle hermetically sealing the connecting portion between the Wheel 7 is rolled along the surface of the article to be ground. a

In view of the construction of FIGS. 10 and 11, it is not necessary that theabrasive member 7' be covered with abrasive material all over its surface. As illustrated in FIG. 11, the abrasive 26' is applied only to the lower half of the member 7'.

Although certain particular embodiments of the invention are herein disclosed for purposes of explanation,

various further modifications thereof, after study of this specification, will, be apparent to those skilled in the art to which the invention pertains. For instance, the abrasive wheel is not limited to be a hollow body. It may be made of a solid but resilient material such as a lump of rubber, or synthetic resin, or a sponge.

What I claim is: 1. Anapparatus for grinding the surface of an article comprising:

a body member; a deformable abrasive wheel rotatably carried by said body member; 7 driving means secured to said body member and operatively connected to said wheel; and a roller member rotatably secured to said body of said wheel;

said roller member causing. a lower portion of said wheel to conform to irregularities in the surface of the article being ground.

2. The apparatus of claim 1 and further including means for adjustably engaging the roller member with saiddeforrnable Wheel.

3. The apparatus of claim 2 wherein said deformable abrasive wheel comprises:

a hollow body capable of being filled with a fluid, said hollow body having projections on its exterior surface thereof;

and a sheet having an abrasive surface on one side thereof, and being provided with grooves on the other side thereof, said grooves engaging the projections of said hollow body.

4. The apparatus of claim 1 and further comprising:

plate members slidably secured to opposite sides of said body member, said roller member being rotatably secured at each end thereofto one of said plate members;

V and means connected to said plate members for selectively causing said roller member to engage said wheel.

5. The apparatus of claim 4 wherein said roller member engages the upper surface of said wheel, the lower surface of said wheel being caused to conform to irregularities in the surface of the article being ground.

6. The apparatus of claim 5 wherein tworollers are rotatably secured to said plate members, said roller members being spaced from each other so as to engage the periphery of said wheel on opposite sides of a diameter drawn through the center of said Wheel and the point of contact of said wheel on the article tobe ground.

I References Cited by the Examiner UNITED STATES PATENTS J. SPENCER OVERHOLSER, Primary Examiner. 

1. AN APPARATUS FOR GRINDING THE SURFACE OF AN ARTICLE COMPRISING: A BODY MEMBER; A DEFORMABLE ABRASIVE WHEEL ROTATABLY CARRIED BY SAID BODY MEMBER; DRIVING MEANS SECURED TO SAID BODY MEMBER AND OPERATIVELY CONNECTED TO SAID WHEEL; AND A ROLLER MEMBER ROTATABLY SECURED TO SAID BODY MEMBER, SAID ROLLER MEMBER ENGAGING THE PERIPHERY OF SAID WHEEL; SAID ROLLER MEMBER CAUSING A LOWER PORTION OF SAID WHEEL TO CONFORM TO IRREGULARITIES IN THE SURFACE OF THE ARTICLE BEING GROUND. 